1. Field of the Invention
It is well known that there are a multitude of machines in which sheets of paper cut to a predetermined size are utilized for one purpose or another. One such machine is the typical office photocopy machine in which sheets of copy paper are stored in the form of a stack of sheets and in which the copy machine produces a copy of an original document. As will be fully apparent hereinafter, the improvement of the present invention is applicable to any other machine in which cut sheet paper is utilized and in which the sheets of paper are stored and are fed seriatim to some processing apparatus. It is even possible that the present invention could be utilized as an independent sheet feeding apparatus from which sheets are fed for a purpose other than being utilized in a machine, such as the input device for a sorter, or for automatically loading of a collator. Other examples are apparent.
2. Prior Art
It has been typical practice heretofore in all such machines or mechanisms which feed sheets of paper stored as a stack to manually deposit a stack of sheets into some form of receptacle or storage member built into the machine or mechanism, and to engage a feeding device with the top most sheet of the stack. Usually the feeding device must be moved out of the way in order for the stack of sheets to be placed in an operative position. More recently, it has been the practice to pre-load a stack of sheets into a removable tray, receptacle or cassette and then insert the tray, receptacle or cassette into the operating machine or feeding apparatus and then engage the feeding device with the topmost sheet. This, of course, eliminates the obvious difficulties of having to handle a stack of loose sheets other than merely placing the stack into an easily accesible tray or receptacle. However, the difficulties associated with operatively engaging the feeding device with the topmost sheet are still present.
As exemplified by these patents, U.S. Pat. Nos. 3,563,535, 3,919,972 and 3,977,666, it is typical to provide removable trays, receptacles or cassettes for storing a stack of sheets in a machine, but in each instance it is necessary for the operator to perform a manual operation on the machine in order to disengage the feeding device of the machine so that the tray or receptacle can be removed and then to perform another operation in order to re-engage the feeding device with the topmost sheet of the stack after the tray or receptacle is inserted into the machine or feeding mechanism, as the case may be.
The present invention eliminates the secondary steps in the loading process since it does not require opening and closing doors, depressing spring loaded supports or moving selection handles when inserting or removing trays, receptacles or cassettes, all as required by the prior art machines. In the present invention, regardless of whether embodied as an improvement in a machine which utilizes sheets of paper or in an independent feeding apparatus, the operator merely pulls the tray, receptacle or cassette out of the machine or feeding apparatus when it is time to replenish the paper and re-insert the tray, receptacle or cassette loaded with paper, and the paper is automatically placed into operative engagement with a feeding device without further manual operations being necessary.